Spark-plug.



G. E. PETERSON.

SPARK PLUG.

APPLIOATIQH FILED JAN. 28,1908.

Patented Feb. 4, 1913.

UNITED STATES PATENT OFFICE.

CHARLES E. PETERSON, OF BROOKLYN, NEW YORK, ASSIGNOR TO MICHIGAN MOTOR SPECIALTIES COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

SPARK-PLUG.

Specification of Letters Patent.

Patented Feb. 4, 1913.

- Application filed January 28, 1908. Serial No. 413,000.

T 0 all whom-it may concern Be it known that- I, CHA LES E. PETER- sox. a citizen of thellnited States, residing at Brooklyn. in' the county of Kings and Generally stated. the invention consists of the novel devices and combinations of de- Vices hereinafterdescribed and defined in the claims.

In the accompanying drawings which illustrate the invention. like characters indicate like parts throughout the several views.

Referring to the drawings; Figure 1, is a transverse. vertical section. in elevation.

(taken approximately on the line ac a" of Fig. showing a spark plug embodying my invention. Fig. 2 is a plan view of the spark plug shownin Fig. 1. some parts be ing broken away and some parts beingsec tioned approximately on the line 9: .23 of vF g- I In the views shown in Figs. 1 and the numeral 1 indicates the body or shell of the plug. which ascommonly constructed is of metal. shell-like in form and threaded externally. thus being adapted to be screwed into an engine cylinder. This shell 1 has a shoulder 2 projecting internally as an offset and extending completely aroundthe interior of the shell. A point 3 of metal proccting outward from the shell. downwardly. constitutes one of the sparking terminals. The other spark terminal is carried by the insulator 1. which prevents electrical com munication between the electrodes except through the spark gap. This insulator is constructed of porcelain. lava. stone or any other refractory and insulating material. A i

shoulder 5 formed in the insulator l and surrounding it externally. is adapted to rest against the shoulder '2 of the shell 1. when said insulator is inserted from below intoi The insulator 1 washer 8. slipped down upon the insulator 1. This washer 8 internally just fits upon the insulator 1 and externally just fits into the upper open end of the shell 1. Thus when the asbestos is pressed down and the.

washer 8 is pressed down upon it. the ashestos will be pressed into the grooves O in the insulator 4 and the insulator 4 will be held firmly in place. To hold the washer in place. pressed against the asbestos between the shell 1 and insulator 4. the upper edge 9 ,of the shell 1 is turned over inwardlv upon the washer 8 as shown.

. It is important to note.tha't in place of the grooves 6 in the insulator at. there maybe any raised projection or fillet or any unevenness in the surface of the insulator 4. such that the packing between the shell 1 and insulator 4 may be pressed around or into this unevenness in the surface of the insulator. The object of this unevenness being to enable the insulator 1 .to be held by the packing between it and the shell 1. itmatters not of what nature this unevenness is.

so long as through itthe packing will retain a firm hold upon the insulator. I

The insulator l as usual. bears a spindle 10. having a head 11. at its lower end. which holds the metal washer 12 in place upon the lower end of the insulator 4C. This washer 12 forms the spark terminal. between which and the spark point 3 there is a gap. over which the spark is formed. The spindle 10 is threaded at its upper end. to receive a lock-nut 13 which holds the spindle firmly in the insulator l. A thumb-nut 11 is adapted to be screwed upon the spindle 10 over the lock-nut 13. Between the lock-nut 13 and thumb-nut 14. the conductor 15. con nected to the battery or other source of current is held. The other terminal from the source of current as customary is grounded upon the engine and thus connects with .theshell 1.

It is important to note that the collar or shoulder 5 in the insulator 4 is adapted to cooperate with the shoulder 2 in the shell 1. that is. the. shoulder 5 presses outwardly is a space between the insulator 4 and the against the shoulder 2 in the shell, thereby QWVhile tlic' insulatord is held in -adapte'd-to grip the rugged or uneven sur insulator, substantially as de- 1 untilthe shoulder 2 further upward inotionjbv its .interaction preventing the insulator.fro1n being forced upward in the shell 1. Therefore in assen1 bling the 'plug the insulator 4 is inserted from the bottom, upward into the shell 1, in the shell prevents in he insulator at! position with respect to the shelll, the. packing 7 is with the shoulder --then forced intb place, cooperating with the depressions in the insulator 4 to prevent the insulator 4 from sllpping downward from its fixed position upward'a'gainst the..shoul der in the shell 1; Vhat I claim is;

L'In-a spark, plug,& shell and an 1nsul,a-- tor; the shell having an internal shoulder surrounding the insulator and the insulator having a collar and having a rugged or uneven surface adjacent to'said collar, said collar cooperating with theshoulder in the surrounding -'shell, in combination with a packing beween the insulator and the shell face of the scribed. a 1

2. In a'spark plug, a shell and -an.insula'- tor; the shell having ,an'internal shoulder surrounding the insulator and the insulator" groo s adjacent to said collar, said collar .0 "perati'ng with"the shoulder in the surhiya collar and having a groove or rounding shell, in combination with a packing between the insulator and the shell- .adapted to cooperate with the groove of grooves in the insulator, to hold the insula- .tor-, substantially as described.-'

3. In a spark plug, a shell and an insulator;the .shell having an internal shoulder- 40- l tor having a collarand having a rugged or surrounding theinsulator and the insula substantially as described. I r 6. In a spark l g, a shell and an described.

tor; the shell havin an internal shoulder surrounding the insuIator and the insulator having a collar and having a rugged or uneven surface adjacent to said collar. said collar cooperating with the shoulderin the surrounding shell, in T combination with a packing between the insulator and the shell adapted to grip the rugged or .uneven'surface of the insulator, the edges of the shell being turned uponthe packing, substantially asdescribed, e I

5. In a spaik plug, a-holdin'g shelland an insulatorythe shell-having an internal collar surrounding theinsula-tor andthe insulator having a collar bearing outwardly against thecollarin the holding shell, said insulator having a rugged or uneven surface adjacent to said collar, in combination with a packing bet-ween theinsulator and the Shell adapted to grip upon said insulator,

insulator; the shell having an, internal shoulder surrounding the insulator and the insulator having a col larand having depressions in' 'its surface adjacent to the collar, in com-= -b'ination with a packing between the ins rlator'and the shell, the packing being pressed into the depressions in the surface offtlre 1 sulator to hold theunsulator inq'Josihon in the shell, the collar of the insulator bearing against the shoulder of theshell, substantially as described. I

T. In a spark plug, a shell and an insulator;. the shell having an internal shoulder surrounding the-insulator and the vin sula tor havin a collar and having projections in its surf ace' ad acent to the colla'r,=1'n com-.

bination with a packing between the his'u-lri-j tor and the 'shelL the packing henlgj=pressed around the projections in the surface of the' insulator to hold the insulator in position, the .collar of the insulatoub'earing against the shoulderof the shell,

In witness whereof, I have hereunto set m hand this 2? da of January 1903,

CHARLES E PETIQRSOX. 'itnesses:

CHARLES G. Reno, T. H Scrnzmrrnrroax.

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